We report on a first-principles study of the troilite phase of iron sulfide (FeS). We show that even if, a few decades ago, this material was thought to be ferroelectric, the structural transition from the high P6_{3}/mmc to the low P6[over ¯]2c symmetry phase does not involve polar instabilities, though the space inversion center symmetry is broken. Our calculations and symmetry analysis never...

1 [Ano98s, BH15, Bre10, PFC02a, Ste02a, Ste14a]. 1-GHz [Ano98s]. 1-terabits [MIM97]. 10 [Loc03]. 10-Gigabit [Gad07, HcF04]. 100 [Kir84a, Pat84, PSW91, ZACM14]. 100-Mops [PSW91]. 1000 [ES84]. 11[Lyl04]. 11/780 [Abr83]. 115 [JBF94]. 11FO4 [ASD05]. 12 [DTB01, Dur96, SS05]. 12-DSP [Dur96]. 1284 [Dia94b]. 1284-1994 [Dia94b]. 13 [KW02]. 1394 [SB00]. 1394-1955 [Dia96d]. 14 [WD03]. 15 [FD04]. 15-Billio...